16:10 hrs updated ET
If students return to the University of Illinois campus in Urbana-Champaign this month, they will be tested for COVID-19. And, then they are tested again.
“We require testing twice a week for access to campus facilities. This is for students, faculty and staff,” explains Rebecca Lee Smith, an associate professor of epidemiology.
The university is one of several beginning ambitious testing regimes as a means of enabling students to safely return to campus.
The University of Illinois is using a saliva-based test developed by an on-campus research team. Students will receive the results within hours. And their first test upon arrival will serve as an “entrance test”, to ensure they are healthy when they return to campus
“Those living in the dorms will be tested at check-in. Others are asked to come to a test location as soon as possible,” says Smith.
This testing strategy is based on the latest evidence that frequent testing can help prevent outbreaks on campuses.
“Fast and frequent, that’s absolutely the key,” says Martin Burke, a chemistry professor at Urbana-Champaign who helped develop the saliva-based test. Not only is it less invasive to collect a saliva sample, compared to doing a nasal swab, Burke and his collaborators have developed a streamlined process in the laboratory that leads to faster results, about 3 to 6 hours on average.
This is critical, says Burke, because in this way the campus “can quickly isolate individuals who test positive.”
This type of regular test regimen is by no means the norm. Many colleges plan to keep online only this fall; others plan one test for entry before the semester begins; others will not require asymptomatic testing. But some campuses are betting on two weekly tests, using a new generation of faster tests.
And, why two tests a week? Diagnostic tests of Coronavirus tend to catch people only in a short window when they are most infected. That is, a newly infected person may test negative if the sample is taken too early before the virus begins to replicate in their body. But, if they were tested again a few days later, the virus would probably be detected.
“That, by testing often, the chances of catching this person when their viral load is up are very high,” says Burke.
Some researchers say it’s time for colleges to embrace testing. “The case for frequency is now pretty strong,” says Rochelle Walensky, a doctor of infectious disease and a professor at Harvard Medical School. “Testing is such an important part of what could be done to get us to a better place on university campuses, and it is currently being completely underutilized,” she says.
As part of a recent study published in JAMA Network Open, Walensky and her staff modeled several scenarios for safely reopened campuses. They found that simply asking students to report symptoms would not be enough.
“We ran thousands of scenarios in our model and we did not even manage to find a single plausible circumstance in which a strategy to simply wait for symptoms to emerge would be enough to contain an outbreak,” says Walensky’s co-author, David Paltiel, a public health professor at Yale School of Medicine.
The reason: “There’s just so much quiet spread,” says Paltiel. A recent analysis published in PNAS found that transmission of silent diseases during the presymptomatic and asymptomatic stages is responsible for the majority of cases.
Paltiel and Walensky’s paper conclude that, in combination with social distance and masking, frequent testing of all students may be required to control outbreaks. And they conclude that “low sensitivity” tests that can produce more false negatives are acceptable.
“You can pick up a large majority of cases in a very short amount of time by testing again and again,” says Paltiel. He says resistance to faster, less sensitive testing is a mistake. “The frequency provides a world of bottles with respect to the accuracy of the test,” he says.
Despite the growing call for more tests on campuses, at present the CDC does not recommend “entrance” tests for all returning students.
Paltiel says this guidance could be dangerous. “It amazes me that the CDC has not updated its guidance, in light of gathering evidence that ‘silent spreaders’ are adding outbreaks,” he says.
The CDC guide says that entrance tests have not been studied systematically.
“A lack of evidence is not the same thing as evidence of a lack of effectiveness,” says Dr. Aaron Carroll, a professor at Indiana University School of Medicine. “From a public health perspective, each case we identify and isolate is better than not.” He claims entrance tests, especially for students on campus, “combined with a robust program of continuous, regular testing of as many people as possible, seems like a good idea.”
The CDC’s guidance on campus testing was updated last June. Now, as the evidence continues to evolve, a spokesman for the agency NPR says they will re-evaluate the guidance in light of the new investigation. “CDC will record this [JAMA Network Open] study to the body of scientific evidence so far regarding student entrance tests and will continue with the evaluation of the guidance, ‘a spokesman wrote in an email.
The agency points to many factors to consider, including “limited availability of dedicated resources and the logistics required for broad testing” on campuses.
It is true that with current testing technology and shortage of supply chain many campuses may not be able to perform tests frequently for all students.
And the kinds of rapid detective tests that some colleges have developed are not yet on the market. The University of Illinois is currently seeking authorization for emergency use of the FDA for its proprietary test, and Yale University received that authorization Saturday for a very similar test. This authorization means that other diagnostic labs can now start using the test.
Researchers at these institutions say the challenge has been to develop a test that will not be subject to supply chain snags – and could deliver faster and faster results. They say they have found a way to work a time-consuming step in the lab analysis of samples, by using heat to “open up” the virus.
“We are losing the most cumbersome step,” said Nathan Grubaugh, an assistant professor of epidemiology at the Yale School of Medicine. “You lose the most expensive step and the most time-consuming.”
The new technology cuts the amount of skilled labor required, both in the collection of sampling and laboratory processing, he says. If approved, these tests can be fairly widespread because commercial labs can license them.
Meanwhile, Carroll says his school, Indiana University, is increasing its supervision and screening with a combination of saliva tests and antigen tests. “We test all students on campus in all of our campuses with anti-test upon arrival,” he explained, and the school develops plans for ongoing testing.
An antigen test, which can detect proteins from the virus, can pick up active infections and deliver results in less than an hour. The FDA says these are reliable if results are positive, but negative results “may need to be confirmed with a molecular test.”
And around the country, campuses continue to adjust their test plans. Harvard University is in phase of new test protocols: Starting August 16, students living on campus dormitories and residences will begin three times a week. Students living on campus at Brandeis University will be tested twice a week (every three or four days).
By comparison, at the University of Georgia, which typically enrolls about 30,000 students, asymptomatic testing is voluntary, and the university says it plans to conduct about 300 tests a day. Copyright 2020 NPR. Visit https://www.npr.org for more.
